The effect of acupuncture on the resting electroencephalograph (EEG) of 14 normal volunteer subjects (4 males and 10 females) was investigated using topographic mapping and quantitative date analysis techniques. Baseline eyes closed EEG data was obtained for several minutes prior to and after session of all acupuncture procedures which consisted of manual manipulation of the Li-4 (Hegu) acupuncture point for period of 30, 60 and 120 seconds. Frequency analysis of the EEG data from each acupuncture event was obtained and compared to the baseline data to show any significant changes in the amplitude spectra over the bandwidth 0.3 to 30 Hz. Averaging the results from the 14 subjects showed an increase in amplitude of the low frequencies up to 2 Hz, and a small decrease in the dominant rhythm on all electrodes. The changes in the alpha and beta bands are similar to those brought about when the attention of the subjects varies during recording and muscle pressure tension is present. However the increase in amplitude of the low frequencies cannot be explained by these mechanisms but pain may contribute to the changes.